“On Water”Effect for Green Click Reaction:Spontaneous Polymerization of Activated Alkyne with“Inert”Aromatic Amine in Aqueous Media

Organic reactions in water have attracted great attention due to their advantages such as unique reaction performance and environmental friendliness.Organic reactions as well as polymerizations in aqueous media have been extensively investigated,and so far,there has been a massive amount of reporting about polymerizations in water.However,reports about click polymerization in water have been rare.Herein,click polymerization of activated alkyne and aromatic amine in aqueous media is developed.The“on water”effect facilitates polymerization in aqueous media better than in organic solvents,and its mechanism is deciphered through experimental data and theoretical calculations.Water participates in the reaction and reduces the energy barrier to some extent.Besides,polymerization makes it possible for aromatic amine with low reactivity to be linked.By using this strategy,polymers with high molecular weights can be obtained in high yields(up to 95.4%).They show good thermal stability and high refractivity.They can be photodegraded.The polymers with tetraphenylethylene moieties show aggregation-induced emission and can be used as materials for generating photopatterns and visualizing agents for specific staining of lysosome in living cells.

Photodegradation-Induced Turn-On Luminescence of Tetraphenylethylene-Based Trithiocarbonate Polymers

Main observation and conclusion Fluorescent intelligent materials have attracted wide attention because of their great potential applications.One major hurdle for the development and application of fluorescent intelligent materials is the aggregation-caused quenching effect in the solid state.Herein,tetraphenylethylene-based trithiocarbonate polymers with satisfactory molecular weights(Mw up to 24900)were synthesized through a one-pot polymerization route under mild conditions.The polymers were non-emissive due to the quenching effect of the trithiocarbonate group.However,upon UV irradiation,the polymers degraded and strong emission from the tetraphenylethylene unit was observed.Such a unique property endows them with great potential applications,such as photopatterning,anti-counterfeit labels,and UV detection.

Bioinspired Hydrogels with Muscle-Like Structure for AIEgen-Guided Selective Self-Healing

Living systems,including human beings,animals,and plants,display the power to self-heal spontaneously after being damaged.The self-healing is usually selective,which means that the healing efficiency is related to the spatial distribution of dynamic interfacial interactions of the two rupturing surfaces.Current artificial systems use noncovalent interactions or dynamic covalent bonds to prepare self-healing materials.However,they can only show nonselective self-healing due to their homogeneous internal structures.Herein,we report the construction of a composite hydrogel Gel-C consisting of three different self-healing hydrogels(Gel-Y,Gel-G,and Gel-O)through the use of classic bilayer hydrogel technology.When the composite hydrogel was cut into two pieces,the relative orientation of the parts was rotated through different angles to study the differences in self-healing.Owing to the heterogeneous internal structure of the composite hydrogel and the recognition specificity of each included hydrogel,the interfacial dynamic interactions distribution of the two rupturing surfaces is diverse.The results of tensile tests demonstrated that these rotated samples exhibited different self-healing efficiencies.This system realized the transformation of artificial materials from nonselective self-healing to selective selfhealing,providing inspiration for the development of novel biological materials and engineering materials.

Metallophilicity-Induced Clusterization:Single-Component White-Light Clusteroluminescence with Stimulus Response

Materials showing metallophilic interactions continue to attract considerable theoretical and experimental attention largely because of their unusual and unanticipated photophysical behavior as well as their unique stimuli-responsive behavior in an aggregate or solid state.Metallophilic interactions are mostly found between metals with either identical(d^(10)–d^(10))or different(s^(2)–d^(8),d^(8)–d^(10))configurations.Among various metallophilic interactions,aurophilic interactions(Au⋯Au)are well-known and widely reported.In this study,a new phosphorescent gold(I)complex,[(CF_(3)Ph)_(3)PAuC≡CPh](TPPGPA)was reported.

Positive/Negative Phototropism:Controllable Molecular Actuators with Different Bending Behavior

Herein,a series of molecular actuators based on the crystals of(E)-2-(4-fluorostyryl)benzo[d]oxazole(BOAF4),(E)-2-(2,4-difluorostyryl)benzo[d]oxazole(BOAF24),(E)-2-(4-fluorostyryl)benzo[d]thiazole(BTAF4),and(E)-2-(2,4-difluorostyryl)benzo[d]thiazole(BTAF24)showed unique bending behavior under UV irradiation.The one-dimensional(1D)crystals of BOAF4 and BTAF4 bent toward light,whereas those of BOAF24 and BTAF24 bent away from light.Although the chemical structures of these compounds are similar,the authors found that F···H–C interaction played a key role in the different molecular packing in structures crystals,which led to the positive/negative phototropism of the actuators.Moreover,theoretical calculations were carried out to reveal the mechanical properties of the crystals.Taking advantage of these photomechanical properties,the authors achieved the potential application in pushing objects,as well as enriching and removing pollutants.Hence,the molecular actuators with different bending behavior could be fabricated by introducing different number of F atom,which may open a novel gate for crystal engineering.